1. Field of the Invention
The present invention relates to a vehicle door opening and closing structure for opening or closing a door main body attached to an opening of a vehicle body.
2. Description of the Related Art
As an opening and closing structure for each door for ingress and egress provided on a vehicle, there are known a swing opening and closing structure for swinging the door through a hinge and a slide opening and closing structure for sliding the door along a side surface of a vehicle body. If the swing opening and closing structure is adopted, the number of parts can be reduced and a vehicle structure can be simplified. However, this structure makes it disadvantageously difficult to open and close the door in a tiny parking lot. If the slide opening and closing structure is adopted, a projection amount of the door can be suppressed. This structure can, therefore, facilitate opening and closing the door even in a tiny parking lot.
In this slide opening and closing structure, a guide rail including a linear portion and a curved portion is incorporated into a vehicle side portion, and a slide door is guided along this guide rail in an opening or closing direction. To open the slide door, the slide door is projected in a vehicle exterior direction along the curved portion of the guide rail, and then the slide door is slidably moved to a fully opened position. Conversely, to close the slide door, the slide door is moved to the curved portion along the linear portion of the guide rail, and then the slide door is pulled inward in a vehicle interior direction along the curved portion. However, in the opening and closing structure in which the slide door is projected or pulled inward by guiding the door along the curved portion of the guide rail, a moving locus of the slide door coincides with a curved shape of the guide rail. Due to this, it is necessary to curve the guide rail greatly according to the projection amount (pulling amount) required for the slide door. The guide rail of this type disadvantageously influences a vehicle structure.
To solve the disadvantages, an opening and closing structure in which a swing mechanism for moving the slide door in a vehicle width direction and a slide mechanism for moving the slide door in a vehicle longitudinal direction are provided separately is developed. This opening and closing structure can suppress an influence of the guide rail on the vehicle body structure since it is unnecessary to provide the guide rail with the curved portion. Further, an opening and closing structure in which a guide rail and a slide door are connected to each other through a bell crank is developed. This opening and closing structure can amplify the pulling amount of the slide door through the bell crank. A curve amount of the guide rail can be, therefore, reduced.
However, the opening and closing structure having the swing mechanism and the slide mechanism provided separately has the following disadvantages. To actuate one of the two mechanisms, the other mechanism needs to be locked. Due to this, an opening and closing operation for the slide door becomes a stepped operation. This makes it disadvantageously difficult to smoothly open and close the slide door. As a result a good operativity cannot be ensured, resulting in degradation in a vehicle quality. Furthermore, if the door opening and closing operation is to be automated by incorporating an electric motor into this opening and closing structure, it is necessary to incorporate the electric motor into each of the swing mechanism and the slide mechanism. This disadvantageously complicates the opening and closing structure and increases manufacturing cost.
The opening and closing structure having the guide rail connected to the slide door through the bell crank has the following disadvantages. Although this structure can smoothly open and close the slide door, the vehicle looks less attractive for the following reasons. The guide rail is incorporated not only into a side sill of the vehicle body but also into the vehicle side surface. Furthermore, since a driving unit as well as the guide rail is incorporated into the side sill, a height of the side sill is increased. This may possibly deteriorate an ingress and egress performance of the vehicle.